Midmark M9® -05x / M11® -05x Sterilizer Main PC Board Test and Repair

WARNING

To prevent risk of shock always disconnect power before removing covers or performing any service procedure.

WARNING

Some procedures require power to be connected with covers removed. Line voltage is present. Use extreme caution to prevent electric shock.

 

Model

 M9 -050, -053 M11 -050, -051, -053
Serial Number All All

VAC Test

For proper test point readings, meter leads need to penetrate PC board conformal coating.

M9/M11 Steam Sterilizer Main PC Board Testing

1.Set meter to VAC.

2.Place meter probes on desired points and check reading.
• AC line voltage in - Not Fused = TP269 and TP272
• AC line voltage in - Fused = TP270 and TP273
• AC out to power supply = TP266 and TP273

For proper voltage readings, the circuit must be connected (loaded) to the component—such as a solenoid valve you are checking.

Meter Reading

Required Action

AC line voltage in - Not Fused (TP269 and TP272) = approximately 115 VAC / 230 VAC

AC line voltage in - Fused (TP270 and TP273) = approximately 115 VAC / 230 VAC

AC out to power supply (TP266 and TP273) = approximately 115 VAC / 230 VAC

PC board is OK.

AC line voltage in - Not Fused (TP269 and TP272) = approximately 0 VAC

AC line voltage in - Fused (TP270 and TP273) = approximately 0 VAC

AC out to power supply (TP266 and TP273) = approximately 0 VAC

Check supply voltage.

Check fuses.

Any other reading

Replace PC board.

VDC Test

For proper test point readings, meter leads need to penetrate PC board conformal coating.

M9/M11 Steam Sterilizer Main PC Board Testing

1.Set meter to VDC.

2.Place meter probes on desired points and check reading.
• 12V Net = TP291 and TP292
• 5V Net = TP294 and TP292
• 3.3V Net = TP293 and TP292
• 12V Isolated = TP271 and TP299

3.When voltage is present, the corresponding LED should light up.
• 12V Net = D24
• 5V Net = D23
• 3.3V Net = D22
• 12V Isolated = D27

Meter Reading

Required Action

12V Net (TP291 and TP292) = approximately 12 VDC

5V Net (TP294 and TP292) = approximately 5 VDC

3.3V Net (TP293 and TP292) = approximately 3.3VDC

12V Isolated (TP271 and TP299) = approximately 12 VDC

PC board is OK.

If VDC reading is low, investigate these items to determine if functioning properly prior to replacing PC board: Door Motor, Hall Effect Sensor, Door Dry Position Switch, CAN to Display, Fans, Water Level Sensor, Steam Temp Sensor, Auto Fill Accessory.

Replace component.

Any other reading

Replace PC board.

M9/M11 Steam Sterilizer Main PC Board Testing

1.Set meter to VDC.

2.Place meter probes on transducer pins 1 and 3* (as shown in the figure above).
Pin position is referenced top to bottom (top pin = 1, bottom pin = 4).

Meter Reading

Required Action

Approximately 5 VDC

PC board is OK.

Any other reading

Replace PC board.